It is well known that when a silver halide color photographic light-sensitive material is subjected to color development, an oxidized aromatic primary amine color developing agent reacts with a coupler to form a dye such as an indophenol, an indoaniline, an indamine, an azomethine, a phenoxazine, a phenazine and the like, thus forming a color image. In order to form a magenta color image, a 5-pyrazolone type coupler, a cyanoacetophenone type coupler, an indazolone type coupler, a pyrazolobenzimidazole type coupler or a pyrazolotriazole type coupler is generally employed.
Magenta color image forming couplers which have been widely used in practice and on which various investigations have been made are almost all 5-pyrazolones. It is known that dyes formed from 5-pyrazolone type couplers are excellent in fastness to heat and light but they have an undesirable absorption of yellow component in the region around 430 nm, which causes color turbidity.
In order to reduce yellow component absorption, a pyrazolobenzimidazole nucleus as described in British Pat. No. 1,047,612, an indazolone nucleus as described in U.S. Pat. No. 3,770,447 and a 1H-pyrazolo[3,2-c][1,2,4]triazole nucleus as described in U.S. Pat. No. 3,725,067 have been proposed as a magenta color image forming coupler skeleton. Further, a 1H-imidazo[1,2-b]pyrazole nucleus as described in Japanese Patent Application No. 23434/83, a 1H-pyrazolo[1,5-b][1,2,4]triazole nucleus as described in Japanese Patent Application No. 45512/83, a 1H-pyrazolo[1,5-d]tetrazole nucleus as described in Japanese Patent Application No. 142801/83 and a 1H-pyrazolo[1,5-b]pyrazole nucleus as described in Japanese Patent Application No. 151354/83 have been recently proposed as novel magenta color image forming coupler skeletons.
The magenta dyes formed from the 1H-pyrazolo-[3,2-c][1,2,4]triazole type couplers as described in U.S. Pat. No. 3,725,067 and British Pat. Nos. 1,252,418 and 1,334,515; the 1H-imidazo[1,2-b]pyrazole type couplers as described in Japanese Patent Application No. 23434/83; the 1H-pyrazolo[1,5-b][1,2,4]triazole type couplers as described in Japanese Patent Application No. 45512/83; the 1H-pyrazolo[1,5-d]tetrazole type couplers as described in Japanese Patent Application No. 142801/83; and the 1H-pyrazolo[1,5-b]pyrazole type couplers as described in Japanese Patent Application No. 151354/83 among these magenta dye image forming couplers show excellent absorption characteristics free from the undesirable absorption of yellow component as described above in a solvent such as ethyl acetate, dibutyl phthalate, etc., and thus they provide preferable color separation.
Of these magenta couplers, however, the 1H-pyrazolo[3,2-c][1,2,4]triazole type couplers have only poor color forming property which results in a decrease in sensitivity and/or a decrease in the maximum color image density obtained Also, azomethine dyes formed from these couplers have remarkably low fastness to light and greatly reduce the desired properties of color photographic light-sensitive materials, in particular, color photographic light-sensitive materials for prints. On the other hand, other novel nitrogen containing heterocyclic 5-membered ring-condensed-5-membered ring type couplers as described above have improved color forming property and provide azomethine dyes having improved light fastness. However, it has been desired in the art to further improve these properties for use in color photographic light-sensitive materials, particularly in color photographic light-sensitive materials for prints.